CN111295549A

CN111295549A - Lighting device for a motor vehicle

Info

Publication number: CN111295549A
Application number: CN201980005428.6A
Authority: CN
Inventors: V·奥林斯基
Original assignee: Bayerische Motoren Werke AG
Current assignee: Bayerische Motoren Werke AG
Priority date: 2018-02-01
Filing date: 2019-01-14
Publication date: 2020-06-16
Anticipated expiration: 2039-01-14
Also published as: CN111295549B; WO2019149507A1; DE102018201533A1; US20210025561A1; US10962192B2

Abstract

The invention relates to an illumination device for a motor vehicle (4), comprising a first light source (1) and a scanner (6), wherein, in the on state of the first light source (1), light (L1) originating from the first light source falls onto the scanner (6) and the scanner (6) executes a scanning movement, wherein by means of the scanning movement a first light spot (SP1) is generated, the light path of the light (L1') of the first light source (1) being changed after passing through the scanner (6) and thereby being moved, wherein a first light function is provided by means of the first light spot, which represents the illumination of a surrounding area of the motor vehicle (4) with visible light. A conversion element (11) is arranged in the beam path of the light (L1 ') of the first light source (1) after passing through the scanner (6), said conversion element converting the light (L1') falling thereon into white light. One or more second light sources (2, 3) are provided, from which light (L2, L3) falls onto the scanner (6) and the scanner executes a scanning movement in the ON state of the respective second light source (2, 3), by means of which scanning movement the light path of the light (L2 ', L3') of the respective second light source (2, 3) changes after passing through the scanner (6) without impinging on a conversion element (11) provided in the illumination device (5), thereby generating a moving second light spot (SP2, SP3) with which the respective second light function is provided.

Description

Lighting device for a motor vehicle

Technical Field

The invention relates to a lighting device for a motor vehicle and to a corresponding motor vehicle.

Background

Scanning motor vehicle lighting devices are known from the prior art, which have a scanner that generates a moving light spot by means of a scanning movement by deflecting the light beam. In this way different types of light distributions, such as low beam and high beam, can be generated. The movement of the light spot is so rapid that it is not perceptible to the human eye.

In order to generate low beam or high beam, conversion elements are usually installed in scanning illumination devices in order to convert the light generated in the illumination device (which is mostly monochromatic) into white light. By using such a conversion element, a relatively unsharp projection is produced, so that the lighting device is not suitable for other light functions than low beam and high beam.

Disclosure of Invention

The object of the present invention is to provide a scanning illumination device for a motor vehicle, with which a plurality of different light functions can be provided in a simple manner.

The task is solved by a lighting device according to claim 1. Further developments of the invention are defined in the dependent claims.

The lighting device according to the invention is intended for motor vehicles, such as passenger cars and, if appropriate, also for trucks. If the interaction between the lighting device and the motor vehicle or a motor vehicle component is described below and in particular in the claims, this is always understood to mean that said interaction occurs when the lighting device is arranged or installed in a motor vehicle. The components of the lighting device which have a corresponding interaction with the motor vehicle or motor vehicle component are therefore designed in such a way that the interaction is brought about when the lighting device is installed or installed in the motor vehicle.

The illumination device according to the invention comprises a first light source and a scanner, wherein, in the on state of the first light source, light originating from the first light source falls onto the scanner and the scanner executes a scanning movement by means of which the light path of the light of the first light source changes after passing through the scanner and a moving first light spot is generated as a result, with which a first light function is provided which effects the illumination of a surrounding area of the motor vehicle with visible light. In this case, a conversion element is arranged in the beam path of the light of the first light source after passing through the scanner, which conversion element converts the light falling thereon into white light.

The illumination device according to the invention is characterized in that one or more second light sources are provided in addition to the first light source, wherein in the on state of the respective second light source the light originating from the second light source falls onto the scanner and the scanner executes a scanning movement by means of which the light path of the light of the respective second light source changes after passing through the scanner without impinging on a conversion element provided in the illumination device. Thereby, for the respective second light source a moving second light spot is generated, with which the respective second light function is provided. In other words, one or more second light functions different from the first light function can be realized by the lighting device. It is ensured here that: the second light function does not use a conversion element in the light path after the scanner and therefore also does not use a conversion element provided in the illumination device, whereby a clearer spot can be achieved.

In a variant of the lighting device according to the invention, the respective second light function can be switched on only when the first light function is switched off. It is also possible that at least a part of the second light function and the first light function can also be switched on simultaneously.

The lighting device according to the invention has the following advantages: in the case of the use of a single scanner, a plurality of optical functions can be realized, wherein a conversion element is used for only one optical function. The additional light function is sufficient without conversion elements and therefore enables a sharp projection of the respective light spot to achieve a particular light distribution. The first light source preferably emits monochromatic light. Depending on the design, the respective second light source can emit monochromatic or colored light and, if necessary, also white light.

In a particularly preferred embodiment, the lighting device according to the invention comprises a headlight or is a headlight, wherein the lighting device is designed to generate at least a part of the low beam distribution and/or the high beam distribution as the first light function.

In a further preferred embodiment, the first light source and/or at least one and preferably all of the second light sources comprise a laser light source which is formed by one or more laser diodes. This enables a high brightness for the respective light function.

In another preferred variant, the scanner mounted in the illumination device according to the invention is a vector scanner with variable scanning speed and variable scanning pattern for moving the first spot and each second spot. Thereby, differently shaped light distributions can be generated in a simple manner. In particular, for example, a light-dark boundary can be generated in the low beam distribution by a corresponding movement of the vector scanner.

In a further preferred variant, the effective distance of at least one second light function (that is to say the maximum distance which light from the respective light point of the lighting device reaches) is smaller than the effective distance of the first light function. Depending on the design, the light distribution of the second light function can overlap the light distribution of the first light function or the two light distributions can do not spatially intersect one another.

In a further embodiment, the second light function (i.e. the second light function or one of the second light functions) is designed in such a way that the second light function representation generates a visible graphic on the ground in the surroundings of the motor vehicle. The term "graphic" is to be understood broadly here. In particular, the graphics may comprise one or more pictograms and/or, if necessary, text. Alternatively or additionally, the graphic may comprise a predefined structure or a predefined pattern on the ground in the surroundings of the motor vehicle. In particular, the second light function can be used to generate a pattern in the near field of the motor vehicle at a distance of 30m or less from the lighting device.

In a further preferred embodiment, the second light function (i.e. the second light function or one of the second light functions) represents a light distribution in the ambient region of the motor vehicle that is generated in the invisible wavelength spectrum. By "invisible" is meant here that the light is not perceptible to the human eye. Preferably, the invisible wavelength spectrum of the light of the second light function lies in the infrared range and particularly preferably in the near infrared range (i.e. in the wavelength spectrum of 780nm to 3 μm). With the aid of this light function, the distance of the object from the motor vehicle can be determined, for example, in conjunction with a suitable evaluation unit. In particular, the light distribution of the second light function can be detected by one or more cameras operating in the respective invisible spectrum of the second light function and the distance to the object can be determined therefrom in a manner known per se, for example on the basis of the time of operation of the light from the lighting device to the camera or by distortion of the invisible light distribution.

In a further variant of the illumination device according to the invention, in the position of the conversion element, in which the conversion element is positioned in the on state of the first light source and the at least one second light source, the optical path of the light of the at least one second light source and in particular of all second light sources is offset from the optical path of the light of the first light source after passing through the scanner, so that the optical path of the light of the at least one second light source does not impinge on the conversion element. In other words, a suitable separation of the light paths allows the light of the at least one second light source not to impinge on the conversion element. With this variant, an embodiment can be realized in which the conversion element is rigidly arranged in the lighting device.

In a further embodiment of the lighting device according to the invention, the switching element is positioned from one position, in which it is positioned in the on state of the first light source, into the other position, for example by means of an electromechanical actuator, when at least one second light source, and in particular each second light source, is switched on. In this case, the light path of the at least one second light source no longer impinges on the conversion element by being positioned in a position in which the light path of the at least one second light source impinges on the conversion element. With this variant, it is achieved by variably positioned conversion elements, which are not used for the respective second light function.

In a further variant of the illumination device according to the invention, an optical arrangement is provided which is arranged behind the scanner in the beam path of the light of the first light source and each second light source and by which the first light spots and each second light spot are generated. In general, the optical arrangement is also referred to as secondary optical element. The optical arrangement preferably comprises one or more optical components (in particular one or more reflectors) and/or one or more lenses, wherein at least one of these components is located not only in the beam path of the light of the first light source but also in the beam path of the light of each second light source. Thereby, one or more components can be used by a plurality of light sources at the same time.

In addition to the above-described lighting device, the invention also relates to a motor vehicle comprising one or more lighting devices according to the invention or preferred variants of said lighting devices.

Drawings

An embodiment of the invention is described in detail below with the aid of fig. 1. The figure shows a schematic view of a variant of the lighting device according to the invention.

Detailed Description

Fig. 1 shows a right-hand part of a front region of a motor vehicle 4, the headlights 5 of which are in each case one embodiment of the lighting device according to the invention. Fig. 1 shows a cartesian coordinate system with an X, Y and Z axis, wherein the ground on which the motor vehicle 4 is located is spanned by the X and Y axis and the height direction of the motor vehicle is represented by the Z axis. In the left-hand part of fig. 1, the hatched part a of the left headlight 5 is again schematically shown in a detail view DA. Here, the detailed view shows a cross section of the headlamp parallel to a plane developed through the X-axis and the Z-axis.

According to the detail view DA, the illumination device 5 comprises three light sources 1, 2 and 3, which are laser light sources. The laser light source 1 is an embodiment of the first light source in the sense of the claims. In contrast, laser light sources 2 and 3 are embodiments of the second light source in the sense of the claims. The laser light source 1 emits monochromatic light in the form of blue laser light in the visible range. The laser light source 2 also emits laser light in the visible range, which may be monochromatic light or, if appropriate, colored or white light, depending on the design, which may be generated by suitable RGB lasers. In contrast, the laser light source 3 generates invisible light in the near infrared range. The light beam emitted from the light source 1 is schematically illustrated in fig. 1 by a dashed line L1. In contrast, the light beam emitted from the light source 2 is represented by a dotted line L2, and the light beam emitted from the light source 3 is represented by a chain line L3.

The illumination device 5 comprises a scanner 6 in the form of a movable micromirror, which is realized very compactly as a MEMS component (MEMS). The scanner is an electrically steerable vector scanner whose micromirrors can not only pivot about an axis perpendicular to the plane of the paper of fig. 1 (indicated by double arrow P) but also tilt about an axis parallel to the plane of the paper of fig. 1 and extending along the plane of the micromirrors. The light beams L1 to L3 of each laser light source 1 to 3 falling thereon are deflected by the scanner 6, so that moving light beams or light beams are generated from these light beams, wherein the respective light beams are denoted by L1 ', L2 ' or L3 ' in fig. 1. The light beam L1 ' is generated by the light beam L1, the light beam L2 ' is generated by the light beam L2, and the light beam L3 ' is generated by the light beam L3. Similar to the light beams L1, L2, and L3, the light beam L1 ' is indicated as a broken line, the light beam L2 ' is indicated as a dotted line, and the light beam L3 ' is indicated as a dot-dash line. Light rays L1 'to L3' represent the beam course in the zero position, again given in fig. 1, of the micromirrors of the scanner 6. By the scanning movement of the scanner, the light beams L1 'to L3' are tilted, wherein the resulting angular range, in which the respective light beams L1 'to L3' can extend, is defined by the thin solid line L.

According to the embodiment of fig. 1, three reflectors 7, 8 and 9 and an exit lens 10 are arranged in the beam path after the scanner 6. The reflectors 7, 8 and 9 and the lens 10 are an embodiment of the optical device in the sense of the claims. The reflectors 8 and 9 perform a pure reflection of the light beam falling thereon, while a conversion element 11 is additionally positioned on the reflector 7, which conversion element effects a conversion of the reflected light into white light. The conversion element is made of a conversion material known per se. For example, a blue/violet laser light source having an emission wavelength of 450nm/405nm uses a phosphor conversion layer composed of a nitrogen nitride phosphor or a nitrogen oxide phosphor or a cerium-doped YAG phosphor.

By means of the reflector 7 with the conversion element 11 situated thereon, only the light beam L1' of the light source 1 is deflected. By means of the reflector 8, only the light beam L2' of the light source 2 is diverted. By means of the reflector 9, only the light beam L3' of the light source 3 is diverted. The light beams resulting from the reflection at the respective reflectors 7 to 9 all fall onto a common exit lens 10 which generates a spot SP1 from the light beam L1 ', a spot SP2 from the light beam L2 ' and a spot SP3 from the light beam L3 ' in front of the motor vehicle. Here, a fast movement of the light spot is caused by the scanning movement of the scanner 6, which is not perceptible to the human eye. In this way, three different light distributions are generated by the respective spots SP1 to SP 3.

The light point SP1 is used to generate a low beam distribution and, if necessary, also a high beam distribution. Since the low beam and the high beam are white light, the conversion element 11 is required in the light path of the light beam L1'. The motion of the scanner 6 is adapted accordingly depending on whether a low beam or a high beam is generated. Unlike spot SP1, a light distribution with a smaller effective distance than the low beam or the high beam is provided with spot SP 2. The light distribution is located in the near field of the motor vehicle at a distance of at most 30m from the front end of the motor vehicle. In the embodiment described here, a pattern is generated on the floor of the motor vehicle by means of the light point SP2, which can be achieved by corresponding control and movement of the scanner 6 associated therewith. At the time of displaying the respective pattern, the light source 1 and, if applicable, the light source 3 are switched off.

By means of the graphics generated by means of the light point SP2, corresponding pictograms or, if appropriate, text can be reproduced on the ground in front of the motor vehicle in order to display information for the driver of the motor vehicle or for other traffic participants. For example, a warning prompt may be output graphically, which: the distance to the vehicle travelling in front is below a predetermined threshold value. If necessary, a predetermined structure or a predetermined pattern can also be projected as a graphic on the ground in front of the motor vehicle. Since the light of the light source 2 does not pass through the conversion element 11, the pattern can be reproduced in a certain color or as a mixture of a plurality of colors. The attention of the driver or other traffic participant of the motor vehicle 4 is thereby diverted to the graphic.

As already mentioned, the laser light source 3 generates laser light that is not visible in the near infrared range. Thus, a light distribution is generated in front of the motor vehicle by means of the light point SP3 that is not perceptible to the driver of the motor vehicle or to other road users. In the embodiment described here, the light distribution is used to detect the distance to an object in front of the motor vehicle. For this purpose, a camera (not shown) is installed in the front of the motor vehicle, which camera detects images of the surroundings in front of the motor vehicle in the near infrared range. The image contains information about the light distribution generated with the point SP 3. These information can be evaluated in a manner known per se in order to determine the distance of the motor vehicle 4 from other objects. In one variant, for example, a TOF camera (TOF ═ time of flight) can be used to determine the distance from the time duration between the emission point SP3 and its reception in the camera. It is also possible for light point SP3 to generate a structured light distribution, wherein three-dimensional information can be extracted by evaluating distortions of the structured light distribution and the distance to an object in front of the motor vehicle can be determined therefrom.

In the embodiment of fig. 1, the conversion element 11 and the reflectors 7 to 9 are rigidly mounted in the luminaire. Here, by appropriately selecting the optical paths of the light beams L1 ' to L3 ', it is ensured that only the light beam L1 ' passes through the conversion element 11. In an alternative embodiment, the beam profiles of each laser light source can also overlap or correspond to one another. In this case, the conversion element is foldable. Such folding may be achieved using suitable electromechanical means. In the unfolded position, only the light source 1 is switched on and the light beam passes the conversion element 11. In the folded position, at least one of the light sources 2 and 3 is switched on and the light source 1 is switched off. Due to the folding of the conversion element, the light beam of the light source 2 or 3 does not pass through the element.

The embodiment of the invention described above has a series of advantages. In particular, in a simple manner, in addition to the light function of the low beam or high beam, additional light functions are integrated in the motor vehicle lighting system in that the same scanner is used for the light source of the additional light functions and in that it is furthermore ensured that no conversion element is used for the additional light functions, which conversion element is provided for generating white light for the low beam or high beam. Thereby, a compact structure of the lighting device can be achieved, wherein at the same time a light function with a sharp light spot is achieved. Furthermore, at least a part of the optical arrangement generating a respective light spot for each light source can be used jointly for the light beams of all light sources, thereby enabling a further reduction of the lighting device.

List of reference numerals

1. 2, 3 light source

4 Motor vehicle

5 head lamp

6 scanner

7. 8, 9 reflectors

10 lens

11 conversion element

A parts of lighting apparatus

DA detailed view

Light beams of L1, L2, L3, L1 ', L2', L3

Boundary of L-angle range

SP1, SP2, SP3 light spots

P double arrow

X, Y, Z coordinates of a Cartesian coordinate System

Claims

1. Lighting device for a motor vehicle (4), comprising a first light source (1) and a scanner (6), wherein, in the on state of the first light source (1), light (L1) originating from the first light source falls onto the scanner (6) and the scanner (6) executes a scanning movement by means of which the beam path of the light (L1 ') of the first light source (1) changes after passing through the scanner (6) and thus produces a moving first light spot (SP1), by means of which a first light function is provided, which represents the illumination of a surrounding area of the motor vehicle (4) with visible light, wherein, in the beam path of the light (L1 ') of the first light source (1), after passing through the scanner (6), a conversion element (11) is provided, which converts the light (L1 ') falling onto the conversion element into white light,

characterized in that one or more second light sources (2, 3) are provided, wherein, in the on state of the respective second light source (2, 3), light (L2, L3) originating from the second light source falls onto the scanner (6) and the scanner (6) executes a scanning movement by means of which the light path of the light (L2 ', L3') of the respective second light source (2, 3) changes after passing through the scanner (6) without impinging on a conversion element (11) provided in the illumination device (5) and thereby generating a moving second light spot (SP2, SP3) with which the respective second light function is provided.

2. A lighting device as claimed in claim 1, characterized in that the lighting device (5) comprises a headlight for a motor vehicle (4), wherein the lighting device (5) is designed for generating at least a part of a low beam distribution and/or a high beam distribution as the first light function.

3. A lighting device as claimed in claim 1 or 2, characterized in that the first light source (1) and/or at least one second light source (2, 3) comprises a laser light source.

4. An illumination device according to any one of the above claims, characterized in that the scanner (6) is a vector scanner with variable scanning speed and variable scanning pattern for the movement of the first spot and each second spot (SP1, SP2, SP 3).

5. A lighting device as recited in any one of the preceding claims, wherein an effective distance of at least one second light function is less than an effective distance of a first light function.

6. A lighting device as claimed in any one of the foregoing claims, characterized in that the second light function represents the generation of a visible graphic on the ground in the surroundings of the motor vehicle (4).

7. A lighting device as claimed in any one of the preceding claims, characterized in that the second light function represents the generation of a light distribution in the non-visible wavelength spectrum in the surrounding area of the motor vehicle (4).

8. A lighting device as recited in claim 7, wherein the invisible wavelength spectrum of light of the second light function is in the infrared range and preferably in the near-infrared range.

9. An illumination device according to any one of the preceding claims, characterized in that in the position of the conversion element (11) in which it is positioned in the on-state of the first light source (1) and the at least one second light source (2, 3), the optical path of the light (L2 ', L3 ') of the at least one second light source (2, 3) after passing the scanner (6) deviates from the optical path of the light (L1 ') of the first light source (1) such that the optical path of the light (L2 ', L3 ') of the at least one second light source (2, 3) does not impinge on the conversion element (11).

10. The illumination device according to one of the preceding claims, characterized in that, when at least one second light source (2, 3) is switched on, the conversion element (11) is positioned from the position in which it is positioned in the switched-on state of the first light source (1) into a further position, wherein the positioning into the further position results in the light path of the at least one second light source (2, 3) no longer impinging on the conversion element (11).

11. An illumination device as set forth in any one of the preceding claims, characterized in that the illumination device (5) comprises an optical arrangement (7, 8, 9, 10) which is arranged after the scanner (6) in the light path of the light (L1 ', L2 ', L3 ') of the first and each second light source (1, 2, 3) and by which the first and each second light spot (SP1, SP2, SP3) is generated.

12. A lighting device as claimed in claim 11, characterized in that the optical arrangement (7, 8, 9, 10) comprises one or more optical components, in particular one or more reflectors (7, 8, 9) and/or one or more lenses (10), wherein at least one of these components (10) is located not only in the light path of the light (L1 ', L2 ', L3 ') of the first light source but also of each second light source (1, 2, 3).

13. Motor vehicle comprising one or more lighting devices (5) according to any of the preceding claims.